Prior to the Industrial Revolution, improvement in the technology for disposal of human wastes was very slow. Virtually no progress was made from the time of the Romans until the 19th century. Outbreaks of epidemics were often spread by the consumption of water contaminated with human wastes. Eventually, the epidemics were curbed by the development of separate and underground systems for treating human wastes.
While modern waste disposal systems have contributed greatly in the diminution of the spread of epidemics, they also demand vast quantities of water for the treatment of human wastes. In the water closet of a standard toilet fixture, where proper functioning is predicated upon the provision of a proper amount of water, usually several gallons of water are required to carry off the waste contained in the toilet bowl.
Through industrialization, urbanization and population growth, many sources of fresh water have been eliminated or so contaminated as to be rendered unfit for human consumption. As a result, the demand for economical use of fresh water has become ever greater, especially in areas where fresh water supply is inadequate.
It has been shown that great amounts of fresh water are consumed in a typical household nowadays, only a small fraction of which is utilized for consumption or food preparation. Most of the water is employed for laundry purposes, baths or showers, washing, watering lawns or gardens, and in the disposal of human wastes.
The term "gray water" commonly refers to the major portion of the water utilized in human activities, which includes all of the waste currently handled by sewage systems excepting only the toilet waste product. While gray water is usually soiled by dirt, soap, detergent, or the like and is not potable, it is quite suitable to be used to flush human wastes in toilet fixtures.
Several patents have been issued with respect to recycling of gray water for use in the water closets of toilet fixtures.
For example, Jennings et al U.S. Pat. No. 3,318,449, Toms U.S. Pat. Nos. 4,115,879, and 4,197,597 all disclose a gray water recycling system consisting of a gray water storage tank, a fresh water feed into the storage tank, a filtration device, and one or more toilet fixtures. A similar system was taught by Reid in U.S. Pat. No. 3,594,825 to be used on human conveyances such as camping trailers and boats.
Although the present invention applies a similar gray water recycling system to flush toilet wastes, it is distinguished over the above-referenced patents in that it ensures that, after flushing, fresh water fills the generally visible and exposed toilet bowl while gray water fills the generally enclosed water closet of the toilet fixture.
All of the prior inventions relating to re-use of gray water for flushing toilet wastes share one common and distinctive drawback, i.e. after flushing, the gray water, which is usually malodorous and discolored, remains in the toilet bowl. As a result, the mere presence of the gray water causes the user much repugnance. More seriously, the gray water in the toilet bowl constitutes a significant health hazard as it is probable that the gray water may splash and come in contact with body parts of the user during use of the toilet. Both shortcomings have been overcome in this invention.